1. Field of the Invention
This invention relates to improvements in locking devices and more particularly, but not by way of limitation, to a lock and door reinforcing plate means for providing a security lock for the door.
2. DESCRIPTION OF THE PRIOR ART
The increasing crime rate involving burglaries has increased the demand for locking devices providing greater security against unauthorized entry into the premises of a building, house, or the like. As a result, there has been activity in the field of locking devices to increase the difficulty of entry into or through a locked door. Some of the older devices are shown in the Patterson U.S. Pat. No. 364,850, issued June 14, 1887, entitled "Combined Key Hole Guide and Escutcheon;" Voight et al U.S. Pat. No. 897,803, issued Sept. 1, 1908, entitled "Lock Construction;" Tinnerman U.S. Pat. No. 2,443,362, issued June 15, 1948, entitled "Fastening Device;" and Clark U.S. Pat. No. 2,568,273, issued Sept. 18, 1951, entitled "Door Lock." More recent attempts to solve the problem of unauthorized entry through locked doors are shown in the Rutherford U.S. Pat. No. 3,513,674, issued May 26, 1970, entitled "Interchangeable Lock Casing;" Deahl U.S. Pat. No. 3,628,356, issued Dec. 21, 1971, entitled "Door Lock Protection Device;" Prahl U.S. Pat No. 3,899,907, issued Aug. 19, 1975, entitled "Cylinder Lock Assembly;" and the Nero U.S. Pat. No. 4,316,371, issued Feb. 23, 1982, entitled "High Safety Bolt Control Devices." Whereas these locking devices have been directed toward security locking of doors, and the like, they have certain disadvantages in that in some instances, the lock cylinder may be punched into or through the door, or pulled or pried out of the door thus removing the effectiveness of the lock. In other instances, the door skin surrounding or adjacent to the lock cylinder may be manually depressed by an intruder, thus creating a space behind the edge of the cylinder through which the intruder may reach and manipulate the lock cylinder tail piece or lock bolt mechanism to gain entry into the area behind the locked door. Some of the presently available safety lock devices include plate members which may be dislodged or removed forceably by an intruder to gain entrance through a locked door. The disadvantages of the present day locking devices will be readily apparent.